Railroad crossings, where vehicle and/or pedestrian paths cross railways, are accompanied by signaling and traffic control equipment. For example, a railroad crossing can include warning lights, warning alarms, gates, or combinations thereof. This equipment is configured to interface with activation and monitoring equipment (e.g., grade crossing predictors and/or event recorders) by wired connection. The wired connection provides a vital interface between equipment (i.e., an interface that is substantially fail-safe).